pots

POTS, or postural orthostatic tachycardia syndrome, is a form of dysautonomia characterized by orthostatic intolerance and an excessive rise in heart rate after standing. In adults, a heart rate increase of at least 30 beats per minute within the first 10 minutes of standing, without a sustained drop in blood pressure, is commonly cited, along with chronic symptoms such as lightheadedness, palpitations, fatigue, brain fog, and exercise intolerance that worsen with posture changes.

Pathophysiology is heterogeneous and may involve impaired autonomic regulation, reduced venous return, low blood volume, and/or increased sympathetic activity. POTS can be primary, with no identifiable cause, or secondary to another condition such as autoimmune disorders, a recent viral illness, or connective tissue disorders like Ehlers-Danlos syndrome. Subtypes include neuropathic POTS (partial autonomic denervation), hyperadrenergic POTS (excessive sympathetic tone), and hypovolemic POTS (reduced blood volume).

Diagnosis relies on clinical history and objective testing. Tilt-table testing or active standing tests demonstrate the heart rate rise with minimal blood pressure change and support the diagnosis, after excluding other causes of dizziness such as dehydration, anemia, thyroid disease, or medication effects.

Management focuses on symptom relief and often combines nonpharmacologic and pharmacologic strategies. Nonpharmacologic measures include higher fluid and salt intake when appropriate, gradual aerobic and resistance exercise, compression stockings, and avoiding prolonged standing. Pharmacologic options are individualized and may include agents to raise blood volume or vascular tone (such as fludrocortisone or midodrine), heart rate–modulating drugs (pyridostigmine, beta-blockers, or ivabradine), and treatment of any underlying or comorbid conditions.

Prognosis varies; many patients improve with time and rehabilitation, though some experience ongoing orthostatic symptoms. POTS most often affects adolescents and young adults and shows a female predominance in reported cases.